Variable speed transmission



Feb. 29, 1944. G. A. LCCHHEAD' 2,342,741

VARIABLE SPEED TRANSMI SSION Filed March 23, 1943 2 Sheets-Sheet 1Inventor 360733 A. Lackkeaafl Feb. 29, 1944. LQCHHEAD 2,342,741

VARIABLE SPEED TRANSMISSION Filed March 2:5, 1943 2 Sheets-Sheet 2 2/ Sg ea zye 4 lockkead I uven'tor Patented Feb. 29, 1944 UNITED STATESPATENT OFFlCE 2,342,741v I f VARIABLE SPEED TRANSMISSION George A.Lochhead, Tekamah, Nebr.

Application March 23, 1943, Serial No. 480,211

I 1 Claim. My invention relates to improvements in variable speedtransmissions for use, more particularly, although not necessarily, inthe line of connection'between the motor and drive shaft of automobilepower plants.

The invention is designed with the primary object in view of providing asimply Constructed, efficient, variable speed transmission adapted forautomatic operation to accelerate the speed of rotation of the driveshaft of an automobile in gradually increasing ratio relative to theincrease in the speed of rotation of the crank, or motor, shaft of thepower plant, and without shock, or jar, or utilizing different gearshifts such as are commonly used, for different speeds.

Another object is to provide a variable speed transmission for thepurposes above set forth and which is economical to manufacture,involves few parts, and requires a minimum of servicing.

Other and subordinate objects are also comprehended by my invention, allof which, together with the precise nature of my improve-- ments, willbe readily understood when the succeeding description and claims areread with reference to the drawings accompanying and forming part ofthis specification.

In said drawings:

Figure 1 is a view in plan of my improved variable speed transmission inits preferred embodiment and with parts shown in section,

Figure 2 is a view in transverse section taken on the line 2-2 of Figure1,

Figure 3 is a view similar to Figure l illustrating the operation of theinvention,

Figure 4 is a view in side elevation of one of the weights of thecentrifugal throw governor, and

Figure 5 is a view in plan of said weight.

Referring to the drawings by numerals, according to my invention, in itspreferred embodiment, the crank, or motor, shaft I of an automobilepower plant, not shown, is equipped with a friction clutch, designated2, includin a pair of driving and driven clutch disks 3, 4, the drivingdisk 3 being laterally movable on the crankshaft I in oppositedirections into and from frictional engagement, respectively, with thedriven disk 4, and the driven disk 4 being freely rotatable about thecrankshaft I and laterally movable thereon in opposite directions toaccelerate and decelerate, respectively, the speed of rotation of thedriven shaft II) of the automobile through the medium of means now to bedescribed.

Fast on the driven disk 4, in the axis thereof, and preferably integraltherewith is an elongated gear 6 axially bored, as at I, for rotary andsliding movement on said shaft I and which tapers from said disk 4. Thedriving-gear 6 meshes with a relatively smaller driven gear 8 taperedoppositely, relative to the taper of the driving gear 6, and which isfast on one end of a motion transmitting shaft 9 inclining toward thefront end of the driven shaft IU of the power plant and opcrativelyconnected at its opposite end to said shaft II) by a universal joint II,for a purpose presently apparent, The driven gear 8 is yieldingly urgedtoward thedriving gear 6 in meshing engagement therewith by means of abearing arm II) in one end of which said shaft 9 is journaled adjacentthe driving gear 6, the other end of said arm being slidably mounted ina fixed tubular support I2 and spring pressed, as at I3, toward the axisof the driving gear 6. The support I2 may be fixed in any suitablemanner, for instance to the chassis, and as represented at I4.

A centrifugal throw governor I5 forms an operating connection betweenthe crankshaft I and the driving disk 3 and functions to move the disk 3in a direction to frictionally engage the same with the driven disk 4.

The centrifugal throw governor I5 comprises a cruciform spider I6 fixedto the crankshaft l, as by a pin I1, and substantially rectangularweights I8 pivotally connected to said spider I6 in degree angularrelation to swing outwardly under the action of centrifugal force andfold inwardly about said shaft I into idle position. The pivotalconnection for each weight I8 comprises a pair of lugs I9 on one end ofthe weight I8 and a pivot pin 20 securing the lugs to said spider I6.The weights l8 are triangular transversely to fold inwardly along thecrankshaft I in side-by-side relation and are longitudinally grooved, asat 2|, to fit around said shaft so as to interfit closely when folded.Operating connections are provided between each weight l8 and thedriving disk 3 comprising, in each instance, a flat rectangular plate 22having one end suitably pivoted, as by side trunnions 23, on the plate,to a pair of ears 24 on one face of the corresponding weight l8 and itsother end similarly pivoted, by trunnions 25, to a pair of ears 26 onone face of the driving disk 3.

A coil spring 21 sleeves onto the crankshaft I between the gear I5 and acollar 28 on said shaft tensions the disk 4 against movement from anormal position in a direction to accelerate the speed of rotation ofthe drive shaft Ill. The normal position of the driven disk 4 isestablished in a manner presently seen.

The operation of my invention will be readily understood. In the normal,lateral position of the driven disk 4 on the crankshaft I, the smallerend of the gear 6 is meshed with the driven gear 8, and in the foldedposition of the weights l8 and normal position of other governor parts,the driving disk 3 is spaced slightly from the driven disk 4 so that thetransmission is idle as regards transmitting-drive to the driven shaftIn. As rotation of the crankshaft i is initiated, the

weights I8 start throwing outwardly, thereby im-' parting end thrust tothe plates 22 which thereby moves the driving disk 3 into engagementwith the driven disk 4 and whereby the driven shaft H) is rotated atslow speed by the small end of the driving gear 6, the gear 8, and themotion transmitting shaft 9. As the speed of rotation of the crankshaftl increases, the outward throw of the weights I8 increases so that theconsequent further endwise movement of the plates 22, and lateralmovement of the driving disk 3 moves the driven disk 4 along the shaft land the driving gear along the gear 8 to progressively enmesh the largerdiameter portions'of said gear 6 with said gear 8, thereby increasingthe ratio of drive between said gears 6 and 8 and correspondinglyaccelerating the speed of rotation of the driven shaft 10 relative tothe speed of rotation of the spring I 3, to permit the requiredcompensating movement of the gear 1 laterally of the driven gear 6. Themanner in which deceleration of the drive shaft 10 is effected underdeceleration of the crankshaft I will be clear from the foregoingdescription of operations.

The foregoing will, it is believed, sufiice to impart a clearunderstanding of my invention without further explanation.

Manifestly, the invention, as described, is susceptible of modificationwithout departing from the inventive concept, and right is hereinreserved to such modifications as fall within the scope of the appendedclaim.

What I claim is:

A transmission interposed in the line of connection between a driveshaft and a driven shaft comprising an,,elongated tapered gear mountedon said drive shaft for adjustment thereon in opposits directions,respectively, spring means urging said'gear in one direction, meansoperatively connecting the tapered gear to the driven shaft including abevel gear constantly meshing with said tapered gear, and means toadjust said tapered gear in the opposite direction in difierent degreeand to simultaneously connect the same to the drive shaft, thesecond-mentioned means further including an inclined motion-transmittingshaft having said bevel gear fast on one end thereof and its other enduniversally connected to the driven shaft, said motion-transmittingshaft being spring-urged toward said bevel gear.

GEORGE A. LOCHHEAD.

